Device for transferring pressings to be sintered from a press producing them from powder materials, to a sintering support

ABSTRACT

The specification describes an apparatus for transferring pressings to be sintered from a press to a sintering support. A suction lifter carries out a movement coupled with a movement of a filling device and pressing die. The lifter receives the pressing in synchronism with the movement of the press from the die and moves it away from the press. A take-over means arranged upstream from the press receives the pressing from the suction lifter. The take-over means passes the pressing received from the suction lifter and lying on the take-over means, onto the sintering support in synchronism with the movement of the press. A receiving means for the sintering base carries out a movement making possible continuous close packing on the sintering support by the receiving means. A control means serves to control the movement of the receiving means in synchronism with the movement of the press.

Marker et a1.

[ DEVICE FOR TRANSFERRING PRESSINGS TO BE SINTERED FROM A PRESS PRODUCING THEM FROM POWDER MATERIALS, TO A SINTERING SUPPORT [75]- lnventors: I-Iarald Marker, Kochel am See;

Josef Leing'tirtner, Bad Heilbrunn, both of Germany [73] Assignee: Dorst-Keramikmaschinen-Bau Inh.

Otto Dorst u. DipL-Ing. Walter Schlegel, Kochel am See, Germany [22] Filed: Sept. 19, 1973 [21] Appl. No.: 398,762

[30] Foreign Application Priority Data Sept. 20, 1972 Germany 2246048 [52] US. Cl 425/78; 214/1 BS; 198/19;

[51] Int. Cl. B65g 47/91 [58] Field of Search 214/1 B, 1 BC, 1 BS, 1 BT,

214/1 B11, 147 T; 198/19, 20 R; 425/78, 406, 455

[56] References Cited UNlTED STATES PATENTS 2,927,707 3/1960 Reed et a1. 214/1 BS X AYA AYA AYAYAY/A\ A A A AV,

[451 July 22,1975

3/1961 Dammert et a1 214/] BC 12/1971 Wilson 214/1 BC [57] ABSTRACT The specification describes an apparatus for transferring pressings to be sintered from a press to a sintering support. A suction lifter carries out a movement coupled with a movement of a filling device and pressing die. The lifter receives the pressing in synchronism with the movement of the press from the die and moves it away from the press. A take-over means arranged upstream from the press receives the pressing from the suction lifter. The take-over means passes the pressing received from the suction lifter and lying on the take-over means, onto the sintering support in synchronism with the movement of the press. A receiving means for the sintering base carries out a movement making possible continuous close packing on the sintering support by the receiving means. A control means serves to control the movement of the receiving means in synchronism with the movement of the press.

2 Claims, 1 Drawing Figure DEVICE FOR TRANSFERRING PRESSINGS TO BE SINTERED FROM A PRESS PRODUCING THEM FROM POWDER MATERIALS, TO A SINTERING SUPPORT BACKGROUND OF INVENTION 1. Field to which Invention Relates The invention relates to a device for transferring pressings to be sintered, for example cutting plates of metallic carbide, from a press producing them from powder substances, to a sintering base or support.

2. The Prior Art It is known that such pressings produced in this manner have a very low green strength and more particularly at the edges are very sensitive to impact.

In the prior art the practice has therefore been to remove the pressings, after they have been uncovered by the die and then to place them on the sintering base or support.

Furthermore, there is the problem of placing the sintering supports as close together as possible in layers in order to achieve satisfactory utilisation of the capacity of the kiln. For fulfilling this task as well it appeared convenient to place the sintering support by hand in position as well, the more so, because for example in the case of the production of pressings with a triangular plan it is preferable to turn each second pressing through 180 with respect to the previous pressing in order to achieve the highest possible density of packing. However, when carrying out the turning of the pressings the fragility of the edges of the pressings means that no mutual contacting of the pressings is allowable. Furthermore, the fact that the large number of shapes existing of such pressings makes necessary varying spacing between the pressings on the sintering support, made it appear preferable for the transfer of the pressings from the press to the sintering support to be undertaken by hand, though possibly with the use of a section lifting device or the like which would, however, then also be operated by hand.

SUMMARY OF INVENTION One aim of the present invention is that of creating an apparatus with which the transfer of the pressings to be sintered from a press producing them by pressing powder-like material to a sintering support is carried out mechanically without the pressings being damaged in any manner and more particularly at the edges.

Furthermore, a further aim of the invention is that of providing for further development of such an apparatus so that it is possible to use the apparatus without difficulty to place the pressings on the sintering supports or plates as close together as possible, possibly turning the pressings in relation to each other if this should be necessary. i

The present invention consists in an apparatus for transferring pressings or blanks to be sintered from a forming press adapted to produce them from powderlike substances to a sintering support, characterised by a. a suction lifter carrying out a movement coupled with a movement of a filling device and pressing die, the lifter being adapted to receive the pressing in synchronism with the movement of the press from the die and to move it away from the press;

b. a take-over means arranged upstream from the press and adapted to receive the pressing from the suction lifter, the take-over means being adapted to pass on the pressing, received from the suction lifter and lying on the take-over means, onto the sintering support in cynchronism with the movement of the press;

c. a receiving means for the sintering base, which carries out a movement making possible continuous close packing on the sintering support by the receiving means; and

d. a control means controlling the movement of the receiving means in synchronism with movement of the press.

Preferably, in accordance with a further development of the invention there is the characterising feature that the take-over means consists of an apparatus part which takes over the pressings from the suction lifter and an apparatus part which raises the pressings from the first-mentioned apparatus part and transport them while hanging over the sintering support arranged on the receiving means.

With this feature it is possible to ensure that the pressings coming from the press are deposited with the same orientation from above and below on the sintering support, something which is of importance more particularly in the case of metal carbide cutting plates and is also desirable.

In accordance with a further development of the invention the take-over means for the sintering base carries out, preferably in steps, a reciprocating movement in lines. In this manner it is possible to ensure that there is a particularly dense charging of the sinter plate even when it is a question of round sinter plates.

On the other hand, if it is a question of triangular cutting plates made of metallic carbide, it is best to mount the individual pressings in such a manner that each second pressing is turned through with respect to the preceding pressing because it is only possible in this manner to achieve the desired high density of packing.

In order to solve this additional problem, it is sufficient to adopt the feature in accordance with a further development of the invention that on the first take-over apparatus part suction means are mounted which can rotate about a vertical axis and which are coupled with the movement of this apparatus part via a planetary drive or transmission. In this manner it is possible to carry out a suitable twisting of the respectively operating suction means on the transfer from the first takeover apparatus part so that for example triangular parts in plan can be twisted through 180 with respect to each other so as to achieve the densest possible packing without the deposited pressings having to be touched again by further means.

In accordance with a further development of the invention there is the further feature that on the second transfer device suction means are provided which are so coupled with the drive and can be so displaced towards the receiving means that on deposit of the pressings on the sintering support the suction means carry out a movement directed towards the latter. With this feature it is possible to ensure that the pressings are mounted in a particularly gentle manner on the sintering support and do not have to be dropped through a vertical distance which may be considerable, something which could lead to a twisting and, however, also to damage of the respective pressing.

In order to provide for a particularly gentle lifting of the pressing from the press there is the feature in accordance with a further development of the invention that the suction lifter carries out a movement directed towards the die for suctionally engaging the pressing and removing it from the die.

Furthermore, there is the feature that the suction lifter upstream from the press is furthermore preferably connected with a gauge pressure producing means, from which it receives a pressure pulse on deposit of the pressing on the take-over device.

Finally, in accordance with the invention there is the feature that receiving means for the sintering support is constructed as a pivoting lever having at least two arms and adapted to turn about a vertical axis. This makes possible a particularly easy interchanging of the sintering supports because after being loaded with the last pressing they can be swung out of the path of the second part of the transfer device while simultaneously the next arm advances the free sintering base under the take-over means.

With the apparatus in accordance with the invention it is possible without difficulty, by a suitable resetting of the control means, to deposit pressings with the most various different shapes and most different spacing between them on the sintering support. The resetting to allow for a change in size of the pressings and also to allow for a change in size of the sintering support is possible with comparatively simple means. The individual movements of the various parts of the apparatus can be coordinated without major difficulties so that the parts of the device cannot collide and therefore there is no danger of pressings which have already been transferred being damaged. Furthermore, damage on transfer of the pressings is also avoided.

DESCRIPTION OF PREFERRED EMBODIMENTS The accompanying drawing shows in its single FIG- URE an embodiment of the subject matter of the invention.

A forming press A which is only diagrammatically shown is provided with a device B, held by means of feed supports 2. The device B serves for transfer of mouldings or pressed blanks produced by pressing in the press A onto sintering or firing supports. A firm connection is ensured with means 3. Synchronously with the filling slide movement of the press A the suction lifter 4 is reciprocated by a linkage system 5 coupled with the press A. This suction lifter 4 serves to raise the pressing from the pressing station of the press A and to transport it out of the press. The pressing is then taken out by a take-over means, which in the case of the embodiment of the invention shown and described consists of two apparatus parts. The first apparatus part comprises a preferably circular plate 6 on which two suction heads 7 and 7a are arranged.

The suction lifter 4 transfers the removed pressing P to the suction head 7 at the end of the movement of the lifter 4 after actuation of a limit switch 8 which is shown diagrammatically and is fixed in relation to the press A. The transfer of the pressing P to the suction head 7 can be aided by switching off the vacuum at the moment of release and simultaneously causing a pressure pulse of short duration to act upon the pressing. However, this feature not only favours the release of the pressing but also ensures that the latter is freed of any powder which may still be adhering to it.

The plate-like apparatus part 6 is caused to start rotating by the plate-like apparatus part 9 as a second part of the transfer device via a toothed belt 10. The plate 9 itself is caused to rotate in steps of 180 each by the pneumatically operated cylinder 11, which is controlled from the press cyclicly.

Owing to this rotary movement the suction head 7 comes into the position 7a and as a result the pressing, indicated by reference Pa comes under a suction head 12, which is attached on the plate 9 by means of a carrier 13. This suction head 12 takes over the pressing Pa from the suction head 7a, which in the meantime has ceased to be acted upon by the vacuum, and conveys the pressing on the next rotation of the plate 9 through 180 into the position Pb, in which the suction head is denoted by reference numeral 120.

Owing to the movement of the suction head 12 or 12a, respectively, on the carrier 13 or 130, respectively, there arises the possibility of vertical movement of the suction head 12 or 12a, respectively, along the carrier 13 or 13a, respectively, for example against the action of a spring, which is not shown, with the help of a cylinder 14, which at the end of the rotary movement of the apparatus part 9 receives a command via a limit switch to press down the suction head 12a and to switch off the vacuum. As a result the pressing Pb is gently deposited on the sintering support 15. The sintering support 15 is arranged together with a further sintering support 15a on a receiving device or means 16, which isconstructed for example as a two-armed lever so that after the termination of the charging or loading of the sintering support 15 the latter is removed by a simple swinging of the receiving means 16 through 180 out of the position adjacent to the suction head 12a and can be replaced by the sintering support 15a which as yet is not loaded, something which can possibly be carried out automatically in synchronism with the device without interruption of working of the press.

The receiving device or means 16 is mounted on a double carriage system 17 so that it is moved in steps and lines under the suction lifter 12a in synchronism with the press A following a rectangular coordinate system. The movement is controlled by pneumatic or electronic control means, not shown, which in accordance with the desired loading pattern of the sinterin g support is suitably programmed and can also provide for openings 18, 18a in the sintering support. Such control means are known as such and therefore do not need to be described in detail.

In order to achieve the optimum density of packing or loading in the case of certain plan forms of the pressings it is necessary to turn the latter before they are deposited on the sintering support. In the case of a triangular form it is for example necessary to provide for twisting or turning through 180 of each second pressing. In the case of the embodiment which is shown and described for the purpose a planetary drive 19 is provided on the first take-over means 6, which moves the suction head 7a each time on the movement from the I receiving position for the pressing P in the discharge forming press having a die; a movable carriage for said support; a lifter; a transfer means having a primary suction head and a transfer plate; said lifter having means for gripping a pressing and lifting it from the die; said lifter being movable to a pressing release position over said suction head; said suction head being adapted to transfer the pressed blank to said plate; said plate being rotatably mounted and means for rotating the same in 180 increments; means for coordinating the operation of said die, suction head and transfer plate; said transfer plate having a secondary suction lifter mounted any loose material from the pressed blank. 

1. In an apparatus for transferring an unsintered pressed blank for a sintered part from a pressing die to a support holding the pressing while it is sintered, a forming press having a die; a movable carriage for said support; a lifter; a transfer means having a primary suction head and a transfer plate; said lifter having means for gripping a pressing and lifting it from the die; said lifter being movable to a pressing release position over said suction head; said suction head being adapted to transfer the pressed blank to said plate; said plate being rotatably mounted and means for rotating the same in 180* increments; means for coordinating the operation of said die, suction head and transfer plate; said transfer plate having a secondary suction lifter mounted thereon; means forcing said suction lifter to lower when said suction lifter is over said support and tO release the suction grip on a pressing when the suction lifter has been lowered; means for moving said carriage in synchronization with said press and secondary suction lifter whereby the pressings are deposited on said support in a close packed prearranged pattern.
 2. An apparatus as recited in claim 1 wherein said lifter has means for releasing a charge of air to remove any loose material from the pressed blank. 